Soldiers in a small group of four or more people who are operating in a combat environment, might find the need to remain mobile while carrying various loads, including their gear and weapons. It is foreseeable that, during their operation, the soldiers will encounter horizontal obstacles, such as canals, rooftop-to-rooftop, gaps, or minefields, that require a crossing device to assist them in avoiding the obstacles.
Crossing devices of various designs have been proposed. The following publications illustrate exemplary designs for crossing devices and associated auxiliaries. U.S. Pat. No. 6,062,621 generally describes a collapsible grappling hook that has a hook on the end. It is spring loaded and opens when thrown. When the grappling hook is thrown, it springs open and locks in place.
U.S. Pat. No. 7,062,811 generally describes a collapsible bridge that uses two triangle supports with two rails to provide the main structure over the gap. The rails are then overlaid with transverse girders that lock into place. The supports on the side and the girder rail system are collapsible. The girders are also stackable and the track is foldable.
U.S. Pat. No. 5,904,025 generally describes a method to reinforce a 90-degree intersection in a structural frame. Four triangular cross section beams come together to form a shear-resisting member of the frame structure. The intersection is formed by cutting and folding the three faces of each beam to increase surface area in contact with the other beam.
In general, the tactical advantages of quick gap crossing outlines two types of crossing: hasty and deliberate. There are nine subtasks possible to successfully cross a gap: Plan, Reconnoiter, Prepare, Deploy Assets, Prepare Assault Site, Secure Far Shore, Provide Crossing, Cross Force, and Reconstitute. These steps are detailed and explained. Communication standards are recorded for recon purposes, and methods of recon are also detailed. Command and control for offensive and retrograde operations are described.
This article applies to our work because our function is to perform hasty crossings. Our product will be involved in the steps from prepare to reconstitute. Also, this article outlines certain features to profile the gap to be crossed—such as condition of access/egress points, location and condition of existing crossing sites, reinforced obstacles, bank height, slope, and soil stability—which could influence the deployment of our device. Methods of reconnaissance may prove useful.
The report by Hornbeck, et al., “Trilateral Design and EST Code for Military Bridging and Gap-crossing Equipment,” May 2005, available at http://www.dtic.mil/dtic/tr/fulltext/u2/a476390.pdf, generally describes the building code for the United States Military Bridging and Gap-Crossing Equipment. It discusses necessary material parameters, load parameters, size requirements, and safety parameters. It also discusses the United States Military system for rating bridges by Military Load Class. It discusses the necessary parameters of a military footbridge as well as commonly used materials.
Commercial ladders are also available, such as the three-way extension ladder found online at: http://www.ladder-guy.com/ladders/; and the Xtend and Climb telescoping ladder found online at: http://besttelescopingladder.com/xtend-climb-785p-aluminum-telescoping-ladder-type-i-professional-series.php.
While the foregoing conventional crossing devices provided a certain level of utility, there still remains an opportunity to provide a new gap crossing device that provides optimal features in term of portability, stackability, compactness, light weight, extension span, rapid deployment, reusability, durability, and ability to reliably support the weight of the soldiers, their gears, and their weapons (e.g., approximately 350 pounds). The new gap crossing device should be amenable for use in military and civilian applications.